The explanation? “A couple of times each year, local dairy farmers start pumping out their holding ponds to spread cow manure out on their fields,” the Press Democrat said. The funk carried through the county, the paper reported, including in Healdsburg and Santa Rosa, where one woman said the aroma made her want to vomit.

This isn’t the first time residents have taken to Twitter to complain about such smells:

I thought I seeped in poop but it turned out to be Sonoma county. #sonomaaroma http://tumblr.com/xqsl628zs